“We began 2017 with great momentum, having achieved significant clinical
and corporate milestones last year, particularly in the fourth quarter,”
said Aimmune CEO Stephen Dilly, M.B.B.S., Ph.D. “In November 2016, we
completed global enrollment of our ongoing Phase 3 PALISADE trial, which
lays a strong foundation for our AR101 Phase 3 development program in
peanut allergy. That same month, we also announced a strategic
investment of $145 million by Nestlé Health Science while retaining full
global rights to AR101 and our pipeline. As a result, we began 2017 in a
strong financial position with approximately $283 million in cash and
investments. Our resources and efforts in 2017 will continue to be
focused largely on execution of our Phase 3 program for AR101. We
continue to expect to have top-line data from PALISADE available around
year-end 2017 and submit regulatory filings in the U.S. and Europe in
late 2018. Our current capital resources fund us through these events.”

Corporate Highlights

Investment by Nestlé Health Science Kicks Off Two-Year Strategic
Collaboration. In November 2016, Aimmune announced that Nestlé
Health Science purchased $145 million of the company’s common stock in a
private placement and that the two companies entered into a two-year
strategic collaboration designed to enable the successful development
and commercialization of innovative food allergy therapies. The
strategic collaboration enables both parties to discuss areas of
interest, including Aimmune’s current and future development programs,
through a newly established pipeline forum. Aimmune maintains worldwide
commercial rights to all of its product candidates, including AR101.

Addition to the Aimmune Board of Directors. In connection with
the Nestlé Health Science equity investment and collaboration, Aimmune
announced that Nestlé Health Science Chief Executive Officer Greg Behar
joined the Aimmune Board of Directors.

Commercial Manufacturing Facility on Track for Completion by End of
2017. Aimmune has completed construction of a commercial
manufacturing facility for AR101 in a leased building at the site of one
of its current contract manufacturers. Equipment installation and
operating systems qualification are ongoing in this new facility.
Aimmune anticipates that this manufacturing facility will be operational
by the end of 2017.

AR101 Phase 3 Program Highlights

Enrollment in PALISADE Complete; Top-Line Results Anticipated Around
the End of 2017. In November 2016, Aimmune announced completion of
enrollment of PALISADE, an international, randomized 3:1, double-blind,
placebo-controlled Phase 3 trial of the efficacy and safety of AR101 in
patients with peanut allergy. A total of 554 patients ages 4–49 years
were enrolled, 90 percent of whom were between the ages of 4 and 17.
Based on recent feedback from the U.S. Food and Drug Administration, the
primary efficacy analysis will now be conducted in the 4–17 age group,
which aligns with the AR101 Breakthrough Therapy Designation population
in Phase 2. The primary endpoint of PALISADE is the proportion of
patients ages 4–17 who tolerate a single dose of 600 mg of peanut
protein, which is equivalent to a cumulative amount of 1,043 mg of
peanut protein, in the exit double-blind, placebo-controlled food
challenge (DBPCFC) after approximately one year on study. Current
expectations are that the up-dosing portion of the study will be
completed by mid-year 2017. From that point, once all patients are
treated for six months on the maintenance dose of 300 mg of AR101 per
day, topline results should become available around year-end 2017.

RAMSES (Real-world AR101 Market-Supporting Experience Study) Planned
to Start in the Second Quarter of 2017. In September 2016, Aimmune
announced plans to initiate RAMSES, a randomized 2:1, double-blind,
placebo-controlled trial, to gain experience with AR101 in a real-world
setting where the DBPCFC is not required for diagnosis of peanut
allergy. Instead of requiring a DBPCFC for entry into RAMSES, patients
will be selected based on stringent entry criteria, including a
well-documented medical history of IgE-mediated reactions to peanut
(including anaphylaxis), skin reactivity, and analyses of
peanut-specific immunological markers. RAMSES will monitor
treatment-emergent adverse events during a six-month up-dosing period.
Patients will then be followed in an open-label manner for at least six
months on the maintenance dose of 300 mg of AR101 per day. The absence
of an entry food challenge may further improve the tolerability profile
of AR101 in early stages of dosing by removing exposure to high levels
of peanut allergen that may otherwise prime the immune system prior to
treatment. Aimmune expects RAMSES to enroll approximately 440 patients
ages 4–17 at multiple sites in the United States and Canada, beginning
in the second quarter of 2017.

ARTEMIS (AR101 Trial in Europe Measuring oral Immunotherapy Success)
Planned to Start in the Middle of 2017. In November 2016, Aimmune
announced plans to initiate ARTEMIS, a randomized 3:1, double-blind,
placebo-controlled trial, in peanut-allergic children and adolescents
ages 4–17 in Europe. ARTEMIS will explore protection at an endpoint of
tolerating a single dose of 1,000 mg of peanut protein, which is
equivalent to a cumulative amount of 2,043 mg of peanut protein, after
nine months of treatment. Patients will undergo approximately six months
of up-dosing and then three months of maintenance therapy at 300 mg of
AR101 per day, followed by an exit DBPCFC. ARTEMIS builds on the
observation that a high proportion of patients in the ARC002 Phase 2
trial of AR101 tolerated a cumulative amount of 2,043 mg of peanut
protein at the nine-month endpoint. ARTEMIS is designed to confirm that
finding in a double-blind, placebo-controlled setting. Aimmune expects
ARTEMIS to enroll approximately 160 patients at multiple sites in Europe
beginning in mid-2017.

ARC004 Continues to Enroll Eligible Patients Who Have Completed
PALISADE. Patients who have completed PALISADE are provided the
opportunity to roll over into the ARC004 trial. Patients who were in the
AR101 treatment arm of PALISADE will continue to receive AR101 in
ARC004. Patients who were in the placebo arm of PALISADE will undergo
up-dosing with AR101 in ARC004 and then continue to maintenance therapy
at the target dose of 300 mg of AR101 per day. The first ARC004 patient
was enrolled into the study in December 2016. ARC004 is designed to test
dose forgiveness and the durability of AR101 treatment response in a
multi-arm structure to inform the potential for reduced frequency of
dosing during the maintenance phase of AR101 therapy.

Fourth Quarter and Full Year Financial Results

Cash, cash equivalents, and investments totaled $282.5 million at
December 31, 2016, compared to $199.8 million at December 31, 2015. The
increase reflects the $145.0 million equity investment by Nestlé Health
Science in November 2016, partially offset by cash used in operations.

For the quarter and year ended December 31, 2016, net loss was $25.0
million and $80.8 million, respectively, compared to a net loss of $16.0
million and $35.8 million for the comparable periods in 2015.

On a per share basis, net loss for the quarter and year ended December
31, 2016, was $0.55 and $1.89, respectively, compared to net loss per
share of $0.39 and $1.88 for the comparable periods in 2015. The
weighted average shares outstanding for the quarter and year ended
December 31, 2016, were 45.5 million and 42.8 million shares,
respectively, compared to 41.6 million and 19.0 million shares for the
comparable periods in 2015. In November 2016, Aimmune agreed to sell 7.6
million newly issued shares of common stock to Nestlé Health Science. At
December 31, 2016, Aimmune had 50.2 million shares of common stock
outstanding.

Research and development expenses for the quarter and year ended
December 31, 2016, were $17.0 million and $54.6 million, respectively,
compared to $10.8 million and $19.8 million for the comparable periods
in 2015. The increases in both periods were primarily due to increased
clinical trial and contract manufacturing costs and additional
personnel-related costs, including stock-based compensation expense, to
support the PALISADE trial.

General and administrative expenses for the quarter and year ended
December 31, 2016, were $8.3 million and $26.9 million, respectively,
compared to $5.4 million and $16.2 million for the comparable periods in
2015. The increases in both periods were primarily due to additional
personnel-related costs, including stock-based compensation expense, to
support the company’s growth.

2017 Financial Guidance

Aimmune provided the following financial guidance for 2017:

Research and development expenses(1)

$95 million – $105 million

General and administrative expenses(1)

$35 million – $40 million

Capital expenditures

Approximately $5 million

(1)Includes stock-based compensation expenses of:

Research and development

$5 million – $7 million

General and administrative

$7 million – $8 million

Conference Call Today at 8 a.m. Eastern Time /
5 a.m. Pacific Time

Aimmune management will host a conference call to discuss its financial
results and provide a general business update today at 8 a.m. Eastern
Time / 5 a.m. Pacific Time. The conference call will be accessible via
the company’s website at www.aimmune.com
on the Events page under Investor Relations. Please connect to the
company’s website at least 15 minutes prior to the start of the
conference call to ensure adequate time for any software download that
may be required to listen to the webcast. Alternatively, please call
1-877-497-1438 (U.S.) or 1-262-558-6296 (international) and provide the
conference ID # 84650109 to join by phone. An archived copy of the
webcast will be available on the company’s website for at least 30 days
after the conference call.

About Aimmune Therapeutics

Aimmune Therapeutics, Inc., is a clinical-stage biopharmaceutical
company developing treatments for life-threatening food allergies. The
company’s Characterized Oral Desensitization ImmunoTherapy
(CODIT™) approach is intended to achieve meaningful levels of protection
by desensitizing patients with defined, precise amounts of key
allergens. Aimmune’s first investigational biologic product using
CODIT™, AR101 for the treatment of peanut allergy, has received the
FDA’s Breakthrough Therapy Designation for the desensitization of
peanut-allergic patients 4-17 years of age and is currently being
evaluated in Phase 3 clinical trials. For more information, please see www.aimmune.com.

Forward-Looking Statements

Statements contained in this press release regarding matters that are
not historical facts are “forward-looking statements” within the meaning
of the Private Securities Litigation Reform Act of 1995. Because such
statements are subject to risks and uncertainties, actual results may
differ materially from those expressed or implied by such
forward-looking statements. Such statements include, but are not limited
to, statements regarding: Aimmune’s 2017 financial guidance; Aimmune’s
expectations for its Phase 3 PALISADE trial of AR101, including the
expected timing of topline data; Aimmune’s expectations regarding the
potential benefits of AR101; Aimmune’s expectations regarding the
sufficiency of its capital resources; Aimmune’s expectations for the
RAMSES and ARTEMIS trials, including the timing and enrollment of these
trials, and the ARC004 trial; Aimmune’s expectations on regulatory
submissions for marketing approval of AR101 in the United States and
Europe, including the timing of these submissions; Aimmune’s
expectations for its commercial manufacturing facility, including the
timing of completion of the facility; and Aimmune’s expectations
regarding potential applications of the CODIT™ approach to treating
life-threatening food allergies. Risks and uncertainties that contribute
to the uncertain nature of the forward-looking statements include: the
expectation that Aimmune will need additional funds to finance its
operations; the company’s ability to initiate and/or complete clinical
trials; the unpredictability of the regulatory process; the possibility
that Aimmune’s clinical trials will not be successful; Aimmune’s
dependence on the success of AR101; the company’s reliance on third
parties for the manufacture of the company’s product candidates;
possible regulatory developments in the United States and foreign
countries; and the company’s ability to attract and retain senior
management personnel. These and other risks and uncertainties are
described more fully in Aimmune's most recent filings with the
Securities and Exchange Commission, including its Annual Report on Form
10-K for the year ended 2016 to be filed on March 15, 2017. All
forward-looking statements contained in this press release speak only as
of the date on which they were made. Aimmune undertakes no obligation to
update such statements to reflect events that occur or circumstances
that exist after the date on which they were made.

This press release concerns a product that is under clinical
investigation and that has not yet been approved for marketing by the
U.S. Food and Drug Administration (FDA) or the European Medicines Agency
(EMA). It is currently limited to investigational use, and no
representation is made as to its safety or effectiveness for the
purposes for which it is being investigated.

AIMMUNE THERAPEUTICS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands)

December 31,2016(unaudited)

December 31,2015 (1)

Assets

Cash and cash equivalents

$

124,010

$

76,677

Short-term investments

124,921

115,158

Prepaid expenses and other current assets

2,749

5,622

Total current assets

251,680

197,457

Long-term investments

33,602

7,992

Property and equipment, net

10,391

2,702

Prepaid expenses and other assets

3,116

4,210

Total assets

$

298,789

$

212,361

Liabilities and Stockholders’ Equity

Current liabilities

$

11,450

$

5,098

Other liabilities

1,367

1,012

Stockholders’ equity

285,972

206,251

Total liabilities and stockholders’ equity

$

298,789

$

212,361

(1)Derived from the audited financial statements,
included in the Company's Annual Report on Form 10-K for the year
ended December 31, 2015.

AIMMUNE THERAPEUTICS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

(Unaudited)

Three Months EndedDecember 31,

Twelve Months EndedDecember 31,

2016

2015

2016

2015

Operating Expenses

Research and development(1)

$

16,958

$

10,766

$

54,642

$

19,816

General and administrative(1)

8,343

5,389

26,885

16,181

Total operating expenses

25,301

16,155

81,527

35,997

Loss from operations

(25,301

)

(16,155

)

(81,527

)

(35,997

)

Interest income, net

225

147

703

181

Net loss

$

(25,076

)

$

(16,008

)

$

(80,824

)

$

(35,816

)

Net loss per common share, basic and diluted

$

(0.55

)

$

(0.39

)

$

(1.89

)

$

(1.88

)

Shares used in computing net loss per basic and diluted share(2)

45,491

41,576

42,751

19,041

(1)Includes employee stock-based compensation expense of:

Three Months EndedDecember 31,

Twelve Months EndedDecember 31,

2016

2015

2016

2015

Research and development

$

1,128

$

2,126

$

4,838

$

2,522

General and administrative

2,420

1,280

7,803

3,635

Total stock-based compensation expense

$

3,548

$

3,406

$

12,641

$

6,157

(2)At December 31, 2016, Aimmune had 50,196,883 shares of
common stock outstanding.